2004 DAEWOO NUBIRA check engine

ENGINE CONTROLS 1F – 7
DAEWOO V–121 BL4
Parameter ValueScaling
A/C RequestYes/NoNo
A/C ClutchOn/OffOff
Fuel Pump CommandOn/OffOn
Closed LoopYes/NoYe s
Throttle At IdleYes/NoNo
O2 Ready (B1–S1)Yes/NoYe s
Knock PresentYes/NoNo
Fan LowOn/OffOn/Off
Fan HighOn/OffOn/Off
TCC Engaged (Only AT)Yes/NoYe s
Park/Neutral (Only AT)P/N and R/N/DP/N
Fuel Level InputVvaries
Fuel Level Output%varies
Fuel Trim Cell–18
G–SensorV1.1 – 3.7 V (Non–ABS Only)
Engine RuntimeHH:MM:SSHours:Minutes:Seconds
* Condition: Warmed up, idle, park or neutral, A/C off
ENGINE DATA DISPLAY TABLE
DEFINITIONS
ECM Data Description
The following information will assist in diagnosing emis-
sion or driveability problems. A first technician can view
the displays while the vehicle is being driven by second
technician. Refer to Powertrain On–Board Diagnostic
(EOBD) System Check for addition information.
A/C Clutch
The A/C Relay represents the commanded state of the
A/C clutch control relay. The A/C clutch should be en-
gaged when the scan tool displays ON.
A/C Pressure
The A/C High Side displays the pressure value of the A/C
refrigerant pressure sensor. The A/C High Side helps to
diagnose the diagnostic trouble code (DTC) P0533.
A/C Request
The A/C Request represents whether the air conditioning
is being requested from the HVAC selector. The input is re-
ceived by the instrument panel cluster and then sent serial
data to the ECM and finally to the scan tool over KWP 2000
serial data.
Air Fuel Ratio
The Air Fuel Ration indicates the air to fuel ratio based on
the Front Heated Oxygen Sensor (HO2S1) inputs. The
ECM uses the fuel trims to adjust fueling in order to at-
tempt to maintain an air fuel ratio of 14.7:1.BARO
The Barometric Pressure (BARO) sensor measures the
change in the intake manifold pressure which results from
altitude changes. This value is updated at ignition ON and
also at Wide Open Throttle (WOT).
Base Injection PWM
Indicates the base Pulse Width Modulation (PWM) or ON
time of the indicated cylinder injector in milliseconds.
When the engine load is increased, the injector pulse width
will increase.
Calculated Air Flow
The calculated air flow is a calculation based on manifold
absolute pressure. The calculation is used in several diag-
nostics to determine when to run the diagnostics.
Desired Idle Speed
The ECM commands the idle speed. The ECM compen-
sates for various engine loads in order to maintain the de-
sired idle speed. The actual engine speed should remain
close to the desired idle under the various engine loads
with the engine idling.
Engine Coolant Temperature
The Engine Coolant Temperature (ECT) sensor sends en-
gine temperature information to the ECM. The ECM sup-
plies 5 volts to the engine coolant temperature sensor cir-
cuit. The sensor is a thermistor which changes internal
resistance as temperature changes. When the sensor is
cold (internal resistance high), the ECM monitors a high
voltage which it interprets as a cold engine. As the sensor
warms (internal resistance decreases), the voltage signal
will decrease and the ECM will interpret the lower voltage
as a warm engine.

1F – 30IENGINE CONTROLS
DAEWOO V–121 BL4
DIAGNOSIS
SYSTEM DIAGNOSIS
DIAGNOSTIC AIDS
If an intermittent problem is evident, follow the guidelines
below.
Preliminary Checks
Before using this section you should have already per-
formed the ”On–Board Diagnostic System Check.”
Perform a thorough visual inspection. This inspection can
often lead to correcting a problem without further checks
and can save valuable time. Inspect for the following con-
ditions:
S Engine control module (ECM) grounds for being
clean, tight, and in their proper location.
S Vacuum hoses for splits, kinks, collapsing and prop-
er connections as shown on the Vehicle Emission
Control Information label. Inspect thoroughly for
any type of leak or restriction.
S Air leaks at the throttle body mounting area and the
intake manifold sealing surfaces.
S Ignition wires for cracks, hardness, proper routing,
and carbon tracking.
S Wiring for proper connections.
S Wiring for pinches or cuts.
Diagnostic Trouble Code Tables
Do not use the Diagnostic Trouble Code (DTC) tables to
try to correct an intermittent fault. The fault must be pres-
ent to locate the problem.
Incorrect use of the DTC tables may result in the unneces-
sary replacement of parts.
Faulty Electrical Connections or Wiring
Most intermittent problems are caused by faulty electrical
connections or wiring. Perform a careful inspection of sus-
pect circuits for the following:
S Poor mating of the connector halves.
S Terminals not fully seated in the connector body.
S Improperly formed or damaged terminals. All con-
nector terminals in a problem circuit should be care-
fully inspected, reformed, or replaced to insure con-
tact tension.S Poor terminal–to–wire connection. This requires
removing the terminal from the connector body.
Road Test
If a visual inspection does not find the cause of the prob-
lem, the vehicle can be driven with a voltmeter or a scan
tool connected to a suspected circuit. An abnormal voltage
or scan tool reading will indicate that the problem is in that
circuit.
If there are no wiring or connector problems found and a
DTC was stored for a circuit having a sensor, except for
DTC P0171 and DTC P0172, replace the sensor.
Fuel System
Some intermittent driveability problems can be attributed
to poor fuel quality. If a vehicle is occasionally running
rough, stalling, or otherwise performing badly, ask the cus-
tomer about the following fuel buying habits:
S Do they always buy from the same source? If so,
fuel quality problems can usually be discounted.
S Do they buy their fuel from whichever fuel station
that is advertising the lowest price? If so, check the
fuel tank for signs of debris, water, or other contam-
ination.
IDLE LEARN PROCEDURE
Whenever the battery cables, the engine control module
(ECM), or the ECM fuse is disconnected or replaced, the
following idle learn procedure must be performed:
1. Turn the ignition ON for 5 seconds.
2. Turn the ignition OFF for 5 seconds.
3. Turn the ignition ON for 5 seconds.
4. Start the engine in park/neutral.
5. Allow the engine to run until the engine coolant is
above 185° F (85°C ).
6. Turn the A/C ON for 10 seconds, if equipped.
7. Turn the A/C OFF for 10 seconds, if equipped.
8. If the vehicle is equipped with an automatic trans-
axle, apply the parking brake. While pressing the
brake pedal, place the transaxle in D (drive).
9. Turn the A/C ON for 10 seconds, if equipped.
10. Turn the A/C OFF for 10 seconds, if equipped.
11. Turn the ignition OFF. The idle learn procedure is
complete.

1F – 32IENGINE CONTROLS
DAEWOO V–121 BL4
ON–BOARD DIAGNOSTIC (EOBD) SYSTEM CHECK
(1.4L/1.6L DOHC)
Circuit Description
The On–Board Diagnostic (EOBD) system check is the
starting point for any driveability complaint diagnosis. Be-
fore using this procedure, perform a careful visual/physi-
cal check of the engine control module (ECM) and the en-
gine grounds for cleanliness and tightness.
The EOBD system check is an organized approach to
identifying a problem created by an electronic engine con-
trol system malfunction.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside the
insulation. Check for poor connections or a damaged har-
ness. Inspect the ECM harness and connections for im-
proper mating, broken locks, improperly formed or dam-
aged terminals, poor terminal–to–wire connection, and
damaged harness.Test Description
Numbers below refer to the step number on the Diagnostic
Chart:
1. The Malfunction Indicator Lamp (MIL) should be
ON steady with the ignition ON and the engine
OFF. If not, go to ”Diagnostic Aids”.
2. Checks the Class 2 data circuit and ensures that
the ECM is able to transmit serial data.
3. This test ensures that the ECM is capable of con-
trolling the MIL and the MIL driver circuit is not
shorted to ground.
4. If the engine will not start, refer to ”Engine Cranks
But Will Not Run” in this section.
7. A scan tool parameter which is not within the typical
range may help to isolate the area which is causing
the problem.
10. This vehicle is equipped with a ECM which utilizes
an Electrically Erasable Programmable Read Only
Memory (EEPROM). The replacement ECM must
be programmed. Refer to the latest Techline proce-
dure for ECM reprogramming.

ENGINE CONTROLS 1F – 33
DAEWOO V–121 BL4
On–Board Diagnostic (EOBD) System Check (1.4L/1.6L DOHC)
StepActionValue(s)YesNo
11. Turn the ignition switch to ON.
2. Observe the Malfunction Indicator Lamp (MIL).
Is the MIL illuminate?–Go to Step 2Go to
”No Malfunction
Indicator Lamp”
21. Turn the ignition switch to LOCK.
2. Install the scan tool to the Data link Connector
(DLC).
3. Turn the ignition switch to ON.
4. Attempt to display the Engine Control Module
(ECM) engine data with the scan tool.
Does the scan tool display the ECM engine data?–Go to Step 3Go to Step 8
31. Using the scan tool output test function, select
the MIL lamp control and command the MIL off.
2. Observe the MIL.
Does the MIL turn OFF?–Go to Step 4Go to
”Malfunction In-
dicator Lamp
on Steady”
4Attempt to start the engine.
Does the engine start and continue to run?–Go to Step 5Go to
”Engine Cranks
But Will Not
Run”
5Select DISPLAY DTC with the scan tool.
Are any Diagnostic Trouble Codes (DTCs) stored?–Go to Step 6Go to Step 7
6Check the display for DTCs P0107, P0108, P0113,
P0118, P0122, P0123, P0712, P1392.
Are two or more of the following DTCs stored?–Go to
”Multiple ECM
Information
Sensor DTCs
Set”Go to applica-
ble DTC table
7Compare the ECM data values displayed on the
scan tool to the typical engine scan data values.
Are the displayed values normal or close to the typi-
cal values?–Go to
”ECM Output
Diagnosis”Go to indicated
component
system check
81. Turn the ignition switch to LOCK.
2. Disconnect the ECM connector.
3. Turn the ignition switch to ON.
4. Check the serial data circuit for an open, short
to ground, or short to voltage. Also check the
DLC ignition feed circuit for an open or short to
ground, and check the DLC ground circuits for
an open.
Is a problem found?–Go to Step 9Go to Step 10
9Repair the open, short to ground, or short to voltage
in the serial data circuit or the DLC ignition feed cir-
cuit.
Is the repair complete?–System OK–
101. Attempt to reprogram the ECM.
2. Attempt to display the ECM data with the scan
tool.
Does the scan tool display ECM engine data?–Go to Step 2Go to Step 11
11Replace the ECM.
Is the replacement complete?–System OK–

1F – 34IENGINE CONTROLS
DAEWOO V–121 BL4
ON–BOARD DIAGNOSTIC (EOBD) SYSTEM CHECK
(1.8L DOHC)
Circuit Description
The On–Board Diagnostic (EOBD) system check is the
starting point for any driveability complaint diagnosis. Be-
fore using this procedure, perform a careful visual/physi-
cal check of the engine control module (ECM) and the en-
gine grounds for cleanliness and tightness.
The EOBD system check is an organized approach to
identifying a problem created by an electronic engine con-
trol system malfunction.
Diagnostic Aids
An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside the
insulation. Check for poor connections or a damaged har-
ness. Inspect the ECM harness and connections for im-
proper mating, broken locks, improperly formed or dam-
aged terminals, poor terminal–to–wire connection, and
damaged harness.Test Description
Numbers below refer to the step number on the Diagnostic
Chart:
1. The Malfunction Indicator Lamp (MIL) should be
ON steady with the ignition ON and the engine
OFF. If not, go to”Diagnostic Aids”.
2. Checks the Class 2 data circuit and ensures that
the ECM is able to transmit serial data.
3. This test ensures that the ECM is capable of con-
trolling the MIL and the MIL driver circuit is not
shorted to ground.
4. If the engine will not start, refer to ”Engine Cranks
But Will Not Run” in this section.
7. A scan tool parameter which is not within the typical
range may help to isolate the area which is causing
the problem.
10. This vehicle is equipped with a ECM which utilizes
an Electrically Erasable Programmable Read Only
Memory (EEPROM). The replacement ECM must
be programmed. Refer to the latest Techline proce-
dure for ECM reprogramming.

ENGINE CONTROLS 1F – 35
DAEWOO V–121 BL4
On–Board Diagnostic (EOBD) System Check (1.8L DOHC)
StepActionValue(s)YesNo
11. Turn the ignition switch to ON.
2. Observe the Malfunction Indicator Lamp (MIL).
Is the MIL illuminate?–Go to Step 2Go to
”No Malfunction
Indicator Lamp”
21. Turn the ignition switch to LOCK.
2. Install the scan tool to the Data link Connector
(DLC).
3. Turn the ignition switch to ON.
4. Attempt to display the Engine Control Module
(ECM) engine data with the scan tool.
Does the scan tool display the ECM engine data?–Go to Step 3Go to Step 8
31. Using the scan tool output test function, select
the MIL lamp control and command the MIL off.
2. Observe the MIL.
Does the MIL turn OFF?–Go to Step 4Go to
”Malfunction In-
dicator Lamp
on Steady”
4Attempt to start the engine.
Does the engine start and continue to run?–Go to Step 5Go to
”Engine Cranks
But Will Not
Run”
5Select DISPLAY DTC with the scan tool.
Are any Diagnostic Trouble Codes (DTCs) stored?–Go to Step 6Go to Step 7
6Check the display for DTCs P0107, P0108, P0113,
P0118, P0122, P0123, P0712, P1392.
Are two or more of the following DTCs stored?–Go to
”Multiple ECM
Information
Sensor DTCs
Set”Go to applica-
ble DTC table
7Compare the ECM data values displayed on the
scan tool to the typical engine scan data values.
Are the displayed values normal or close to the typi-
cal values?–Go to
”ECM Output
Diagnosis”Go to indicated
component
system check
81. Turn the ignition switch to LOCK.
2. Disconnect the ECM connector.
3. Turn the ignition switch to ON.
4. Check the serial data circuit for an open, short
to ground, or short to voltage. Also check the
DLC ignition feed circuit for an open or short to
ground, and check the DLC ground circuits for
an open.
Is a problem found?–Go to Step 9Go to Step 10
9Repair the open, short to ground, or short to voltage
in the serial data circuit or the DLC ignition feed cir-
cuit.
Is the repair complete?–System OK–
101. Attempt to reprogram the ECM.
2. Attempt to display the ECM data with the scan
tool.
Does the scan tool display ECM engine data?–Go to Step 2Go to Step 11
11Replace the ECM.
Is the replacement complete?–System OK–

1F – 36IENGINE CONTROLS
DAEWOO V–121 BL4
MULTIPLE ECM INFORMATION SENSOR DTCS SET
Circuit Description
The Engine Control Module (ECM) monitors various sen-
sors to determine engine operating conditions. The ECM
controls fuel delivery, spark advance, transaxle operation,
and emission control device operation based on the sen-
sor inputs.
The ECM provides a sensor ground to all of the sensors.
The ECM applies 5 volts through a pull–up resistor and
monitors the voltage present between the sensor and the
resistor to determine the status of the Engine Coolant
Temperature (ECT) sensor, the Intake Air Temperature
(IAT) sensor. The ECM provides the Exhaust Gas Recir-
culation (EGR) Pintle Position Sensor, the Throttle Posi-
tion (TP) sensor, the Manifold Absolute Pressure (MAP)
sensor, and the Fuel Tank Pressure Sensor with a 5 volt
reference and a sensor ground signal. The ECM monitors
the separate feedback signals from these sensors to de-
termine their operating status.
Diagnostic Aids
Be sure to inspect the ECM and the engine grounds for be-
ing secure and clean.
A short to voltage in one of the sensor circuits can cause
one or more of the following DTCs to be set: P0108,
P0113, P0118, P0123, P1106, P1111, P1115, P1121,
P0463, P0533.
If a sensor input circuit has been shorted to voltage, en-
sure that the sensor is not damaged. A damaged sensor
will continue to indicate a high or low voltage after the af-
fected circuit has been repaired. If the sensor has been
damaged, replace it.
An open in the sensor ground circuit between the ECM and
the splice will cause one or more of the following DTCs to
be set: P0107, P0108, P0113, P0118, P0122, P0123,
P1106, P1111, P1115, P1121, P0462, P0532.
A short to ground in the 5 volt reference circuit or an open
in the 5 volt reference circuit between the ECM and the
splice will cause one or more of the following DTCs to be
set: P0107, P0112, P0117, P0122, P1107, P1112, P1114,
P1122, P0462, P0532.Check for the following conditions:
S Inspect for a poor connection at the ECM. Inspect
harness connectors for backed–out terminals, im-
proper mating, broken locks, improperly formed or
damaged terminals, and poor terminal–to–wire con-
nection.
S Inspect the wiring harness for damage. If the har-
ness appears to be OK, observe an affected sen-
sor ’s displayed value on the scan tool with the igni-
tion ON and the engine OFF while moving
connectors and wiring harnesses related to the af-
fected sensors. A change in the affected sensor’s
displayed value will indicate the location of the fault.
Test Description
Number(s) below refer to the step number(s) on the Diag-
nostic Table.
1. The Powertrain On–Board Diagnostic (EOBD) Sys-
tem Check prompts the technician to complete
some basic checks and store the freeze frame and
failure records data on the scan tool if applicable.
This creates an electronic copy of the data taken
when the malfunction occurred. The information is
then stored on the scan tool for later reference.
9. A faulty EGR valve can leak a small amount of cur-
rent from the ignition feed circuit to the 5 volt refer-
ence circuit. If the problem does not exist with the
EGR valve disconnected, replace the EGR valve.
0. If a sensor input circuit has been shorted to voltage,
ensure that the sensor has not been damaged. A
damaged IAT or ECT sensor will continue to indi-
cate a high voltage or low temperature after the
affected circuit has been repaired. A damaged ACT,
TP, MAP, Fuel Tank Pressure, or EGR Pintle Posi-
tion sensor will indicate a high or low voltage or
may be stuck at a fixed value after the affected cir-
cuit has been repaired. If the sensor has been dam-
aged, replace it.
21. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM re-
programming.

ENGINE CONTROLS 1F – 37
DAEWOO V–121 BL4
Multiple ECM Information Sensor DTCs Set
StepActionValue(s)YesNo
1Perform an On–Board Diagnostic (EOBD) system
check.
Is the check complete.–Go to Step 2Go to
”On–Board
Diagnostic Sys-
tem Check”
21. Turn the ignition switch to LOCK.
2. Disconnect the Engine Control Module (ECM)
connector.
3. Turn the ignition switch to ON.
4. Check the 5V reference circuit for the following
conditions:
S Poor connection at the ECM.
S Open between the ECM connector affected
sensors shorted to ground or voltage.
5. If a problem is found, locate and repair the
open or short circuit as needed.
Is a problem found?–Go to Step 19Go to Step 3
31. Check the sensor ground circuit for the follow-
ing conditions:
S Poor connection at the ECM or affected
sensors.
S Open between the ECM connector and the
affected sensors.
2. If a problem is found, repair it as needed.
Is a problem found?–Go to Step 19Go to Step 4
4Measure the voltage of the Exhaust Gas Recircula-
tion (EGR) Pintle Position Sensor signal circuit be-
tween ECM harness connector and ground.
Does the voltage near the specified value?0 VGo to Step 5Go to Step 9
5Measure the voltage of the Manifold Absolute Pres-
sure (MAP) sensor signal circuit between the ECM
harness connector and ground.
Does the voltage near the specified value?0 VGo to Step 6Go to Step 12
6Measure the voltage of the Throttle Position (TP)
sensor signal circuit between the ECM harness con-
nector and ground.
Does the voltage near the specified value?0 VGo to Step 7Go to Step 12
7Measure the voltage of the Intake Air Temperature
(IAT) sensor signal circuit between the ECM har-
ness connector and ground.
Does the voltage near the specified value?0 VGo to Step 8Go to Step 13
8Measure the voltage of the Engine Coolant Temper-
ature (ECT) sensor signal circuit between the ECM
harness connector and ground.
Does the voltage near the specified value?0 VGo to Step 16Go to Step 14
91. Disconnect the EGR valve connector.
2. Measure the voltage of the EGR Pintle Position
sensor signal circuit between the ECM harness
connector and ground.
Does the voltage near the specified value?0 VGo to Step 10Go to Step 15